In space, to maintain in operational condition a communications satellite, it requires operators sustained training.

Astronauts have many tasks to be done during their time in space. Teams can both operate the advanced robotics hardware to participate in the realization of scientific experiments for research teams remained on Earth. They are also responsible for various tasks such as repair, maintenance or servicing of the systems and equipping the spacecraft and even cooking!
During a mission, the astronauts may be asked to do the work of a scientist, a construction worker, a specialist telecommunications technician, a doctor or a pilot. Many of tasks sometimes exceed the number of hours available to achieve them. This is why the control center on Earth lay down in advance, detailed schedules for each crew member to enable them to perform as much work as possible, while reserving them time to rest or do exercises to maintain good physical health.